1. Field of the Invention
This invention relates generally to digital subscriber line (DSL) systems and relates more particularly to a dual-line DSL system and method.
2. Description of the Background Art
Digital Subscriber Line (DSL) technology has existed for several years. There are some significant competing broadband technologies, such as cable and satellite television and wireless technologies such as mobile multipoint distribution services (MMDS) and local multipoint distribution services (LMDS). Some implementations of these competitive services may be better suited to video-on-demand services than current DSL technology, but not well suited to traditional data communications or interactive voice and video applications. For these applications, DSL may have the advantages of greater upstream bandwidth and lower latency.
Hence, there is a need to improve DSL technology data rates so as to potentially deliver services such as video-on-demand in an effective manner. DSL service providers, therefore, generally need to increase the downstream data rate by about a factor of two to provide video-on-demand services to a large percentage of their customers. The service providers would prefer to increase the downstream data rate without running new copper wires from central offices to customer premises, which would likely be cost prohibitive.
The performance of a DSL system may be affected by several factors, including but not limited to, cable attenuation, Gaussian noise, near end cross talk, far end cross talk, impulse noise, and dispersion. Techniques for improving DSL data rates should address some of these limitations on DSL system performance.